Abnormal activation of the social brain during face perception in autism

ASD involves a fundamental impairment in processing social-communicative information from faces. Several recent studies have challenged earlier findings that individuals with autism spectrum disorder (ASD) have no activation of the fusiform gyrus (fusiform face area, FFA) when viewing faces. In this study, we examined activation to faces in the broader network of face-processing modules that comprise what is known as the social brain. Using 3T functional resonance imaging, we measured BOLD signal changes in 10 ASD subjects and 7 healthy controls passively viewing nonemotional faces. We replicated our original findings of significant activation of face identity-processing areas (FFA and inferior occipital gyrus, IOG) in ASD. However, in addition, we identified hypoactivation in a more widely distributed network of brain areas involved in face processing [including the right amygdala, inferior frontal cortex (IFC), superior temporal sulcus (STS), and face-related somatosensory and premotor cortex]. In ASD, we found functional correlations between a subgroup of areas in the social brain that belong to the mirror neuron system (IFC, STS) and other face-processing areas. The severity of the social symptoms measured by the Autism Diagnostic Observation Schedule was correlated with the right IFC cortical thickness and with functional activation in that area. When viewing faces, adults with ASD show atypical patterns of activation in regions forming the broader face-processing network and social brain, outside the core FFA and IOG regions. These patterns suggest that areas belonging to the mirror neuron system are involved in the face-processing disturbances in ASD.     

Social attribution in children with high functioning autism and Asperger syndrome: An exploratory study in the Chinese setting

The present study aimed to examine social attribution in children with high-functioning autism (HFA) and Asperger's syndrome (AS). A sample of 20 boys (9 with HFA and 11 with AS) and 20 age-matched controls were recruited for this study. All participated in two tasks measuring social attribution ability, the conventional Social Attribution Task (SAT) and a modified version with animals rather than shapes (mSAT). They also completed a battery of neuropsychological tests. Compared to typically developing controls, children with autism spectrum disorders were impaired on some measures in both SATs. However, group differences in ‘theory-of-mind’ indices were only significant in the mSAT, with the ASD group performing more poorly than controls. In addition, the scores in person index of both versions of the SAT correlated with executive function in children with HFA/AS. The current study found the mSAT paradigm was especially sensitive to ToM difficulties in young Chinese children with HFA/AS. Social attribution in children with HFA/AS, unlike neurotypical children, was related to executive function ability, suggesting these psychological domains are not distinct in children with autism spectrum disorders.     

Brief Report: The Impact of Subcortical Band Heterotopia and Associated Complications on the Neuropsychological Functioning of a 13-year-old Child

Motor impairment in children with Asperger syndrome (AS) or high functioning autism (HFA) has been reported previously. This study presents results of a quantitative assessment of neuromotor skills in 14–22 year old HFA/AS. Sixteen HFA/AS and 16 IQ-matched controls were assessed by the Zurich Neuromotor Assessment (ZNA). The HFA/AS group showed strongest impairments of dynamic balance skills and diadochokinesis. Motor abilities were associated with degree of social withdrawal in the full sample and severity of current autistic symptoms in the HFA/AS group. Similar motor patterns as in younger children were found in the older adolescents. The association of autistic symptoms with motor performance points towards an essential role of motor impairment in autism spectrum disorders.     

Quantitative Assessment of Neuromotor Function in Adolescents with High Functioning Autism and Asperger Syndrome

Background: Motor impairment in children with Asperger Syndrome (AS) or High functioning autism (HFA) has been reported previously. This study presents results of a quantitative assessment of neuromotor skills in 14–22 year old HFA/AS. Methods: 16 HFA/AS and 16 IQ-matched controls were assessed by the Zurich Neuromotor Assessment (ZNA). Results: The HFA/AS group showed strongest impairments of dynamic balance skills and diadochokinesis. Motor abilities were associated with degree of social withdrawal in the full sample and severity of current autistic symptoms in the HFA/AS group. Conclusion: Similar motor patterns as in younger children were found in the older adolescents. The association of autistic symptoms with motor performance points towards an essential role of motor impairment in autism spectrum disorders.     

Gaze-fixation, brain activation, and amygdala volume in unaffected siblings of individuals with autism.

BACKGROUND: The broad autism phenotype includes subclinical autistic characteristics found to have a higher prevalence in unaffected family members of individuals with autism. These characteristics primarily affect the social aspects of language, communication, and human interaction. The current research focuses on possible neurobehavioral characteristics associated with the broad autism phenotype. METHODS: We used a face-processing task associated with atypical patterns of gaze fixation and brain function in autism while collecting brain functional magnetic resonance imaging (fMRI) and eye tracking in unaffected siblings of individuals with autism. RESULTS: We found robust differences in gaze fixation and brain function in response to images of human faces in unaffected siblings compared with typically developing control individuals. The siblings' gaze fixations and brain activation patterns during the face processing task were similar to that of the autism group and showed decreased gaze fixation along with diminished fusiform activation compared with the control group. Furthermore, amygdala volume in the siblings was similar to the autism group and was significantly reduced compared with the control group. CONCLUSIONS: Together, these findings provide compelling evidence for differences in social/emotional processing and underlying neural circuitry in siblings of individuals with autism, supporting the notion of unique endophenotypes associated with the broad autism phenotype.     

Visual search for basic emotional expressions in autism; impaired processing of anger,fear and sadness,but a typical happy face advantage

Facial expression recognition was investigated in 20 males with high functioning autism (HFA) or Asperger syndrome (AS), compared to typically developing individuals matched for chronological age (TD CA group) and verbal and non-verbal ability (TD V/NV group). This was the first study to employ a visual search, “face in the crowd” paradigm with a HFA/AS group, which explored responses to numerous facial expressions using real-face stimuli. Results showed slower response times for processing fear, anger and sad expressions in the HFA/AS group, relative to the TD CA group, but not the TD V/NV group. Reponses to happy, disgust and surprise expressions showed no group differences. Results are discussed with reference to the amygdala theory of autism.     

Defining the Intellectual Profile of Asperger Syndrome: Comparison with High-Functioning Autism

Asperger syndrome (AS) is a disorder of early childhood characterized by autistic social deficits, subtle communication impairment, and excessive isolated interests. There is no history of language delay or of mental retardation. Despite its increasing popularity as a distinct condition, its diagnostic validity remains uncertain. It is still unclear to what extent AS differs from autism with normal intelligence sometimes referred to as high-functioning autism (HFA). However, some reports have suggested that persons with AS possess a distinct profile on tests of intelligence characterized by a high verbal IQ and a low performance IQ, whereas in most cases with HFA, the pattern is reversed. Since few studies have directly compared AS subjects with HFA controls using unmodified diagnostic criteria and standardized measures of assessment, in this report we compared 22 AS subjects with 12 HFA controls, matched on age, sex and level of intelligence. As a group, subjects with AS showed a higher verbal IQ and higher scores on information and vocabulary subtests than those with HFA. However, scores of several AS and HFA subjects showed a mixed pattern. Implications of these findings are discussed in the context of the validity of Asperger Syndrome.     

Social intelligence in the normal and autistic brain: an fMRI study.

There is increasing support for the existence of 'social intelligence' [Humphrey (1984) Consciousness Regained], independent of general intelligence. Brothers et al. 1990) J. Cog. Neurosci., 4, 107-118] proposed a network of neural regions that comprise the 'social brain': the orbito-frontal cortex (OFC), superior temporal gyrus (STG) and amygdala. We tested Brothers' theory by examining both normal subjects as well as patients with high-functioning autism or Asperger syndrome (AS), who are well known to have deficits in social intelligence, and perhaps deficits in amygdala function [Bauman & Kemper (1988) J. Neuropath. Exp. Neurol., 47, 369]. We used a test of judging from the expressions of another person's eyes what that other person might be thinking or feeling. Using functional magnetic resonance imaging (fMRI) we confirmed Brothers' prediction that the STG and amygdala show increased activation when using social intelligence. Some areas of the prefrontal cortex also showed activation. In contrast, patients with autism or AS activated the fronto-temporal regions but not the amygdala when making mentalistic inferences from the eyes. These results provide support for the social brain theory of normal function, and the amygdala theory of autism.     

Repetitive Behavior Profiles in Asperger Syndrome and High-Functioning Autism

Although repetitive behaviors are a core diagnostic domain for autism spectrum disorders, research in this area has been neglected. This study had two major aims (1) to provide a detailed characterization of repetitive behaviors in individuals with Asperger Syndrome (AS), high-functioning autism (HFA), and typically developing controls (TD); and (2) to examine whether differences in repetitive behavior profiles could provide evidence for the external validity of AS separate from HFA. Specifically, it was hypothesized that circumscribed interests would be more prevalent and cause more impairment in the AS group than the HFA group, while the reverse would be true for other categories of repetitive behavior. The parent(s) of 61 children and adolescents (19 with AS, 21 with HFA, and 21 TD) completed two interviews focused specifically on lifetime and current repetitive behavior symptoms. No reliable differences in repetitive behavior between AS and HFA children were found. Results suggested that circumscribed interests differ in developmental course from the three other DSM-IV-TR categories of repetitive behavior. Internal consistency among the four DSM-IV-TR categories of repetitive behavior was high, =.84, providing evidence for a unitary repetitive behaviors factor. The importance of expanding research in the repetitive behavior domain is highlighted as part of the necessary integration of behavioral and neurobiological approaches to understanding the etiology of autism.     

Levels of emotional awareness and autism: an fMRI study

Autism is associated with an inability to identify and distinguish one's own feelings. We assessed this inability using alexithymia and empathy questionnaires, and used fMRI to investigate brain activity while introspecting on emotion. Individuals with high functioning autism/Asperger syndrome (HFA/AS) were compared with matched controls. Participants rated stimuli from the International Affective Picture System twice, once according to the degree of un/pleasantness that the pictures induced, and once according to their color balance. The groups differed significantly on both alexithymia and empathy questionnaires. Alexithymia and lack of empathy were correlated, indicating a link between understanding one's own and others' emotions. For both groups a strong relationship between questionnaire scores and brain activity was found in the anterior insula (AI), when participants were required to assess their feelings to unpleasant pictures. Regardless of self-reported degree of emotional awareness, individuals with HFA/AS differed from controls when required to introspect on their feelings by showing reduced activation in self-reflection/mentalizing regions. Thus, we conclude that difficulties in emotional awareness are related to hypoactivity in AI in both individuals with HFA/AS and controls, and that the particular difficulties in emotional awareness in individuals with HFA/AS are not related to their impairments in self-reflection/mentalizing.     

The French Version of the Autism-Spectrum Quotient in Adolescents: A Cross-Cultural Validation Study

We assessed the accuracy of the French version of the Autism Spectrum Quotient (AQ) in adolescents with Asperger syndrome (AS) and high-functioning autism (HFA) compared to healthy controls and adolescents with psychiatric disorders (PDs). Three groups of adolescents, aged 11–18, were assessed: 116 with AS/HFA (93 with IQ ≥ 85 and 20 with 70 ≤ IQ < 85), 39 with other PDs, and 199 healthy controls. The AS/HFA group scored significantly higher than the healthy control and PD groups. A cut-off score of 26 was used to differentiate the autism group from healthy controls with 0.89 sensitivity and 0.98 specificity. Scores did not vary by age or sex.     

A failure to grasp the affective meaning of actions in autism spectrum disorder subjects

The ability to grasp emotional messages in everyday gestures and respond to them is at the core of successful social communication. The hypothesis that abnormalities in socio-emotional behavior in people with autism are linked to a failure to grasp emotional significance conveyed by gestures was explored. We measured brain activity using fMRI during perception of fearful or neutral actions and showed that whereas similar activation of brain regions known to play a role in action perception was revealed in both autistics and controls, autistics failed to activate amygdala, inferior frontal gyrus and premotor cortex when viewing gestures expressing fear. Our results support the notion that dysfunctions in this network may contribute significantly to the characteristic communicative impairments documented in autism.     

Abnormal Activation of the Social Brain Network in Children with Autism Spectrum Disorder: An fMRI Study

Objective

The aim of this study is to investigate abnormal findings of social brain network in Korean children with autism spectrum disorder (ASD) compared with typically developing children (TDC).

Methods

Functional magnetic resonance imaging (fMRI) was performed to examine brain activations during the processing of emotional faces (happy, fearful, and neutral) in 17 children with ASD, 24 TDC.

Results

When emotional face stimuli were given to children with ASD, various areas of the social brain relevant to social cognition showed reduced activation. Specifically, ASD children exhibited less activation in the right amygdala (AMY), right superior temporal sulcus (STS) and right inferior frontal gyrus (IFG) than TDC group when fearful faces were shown. Activation of left insular cortex and right IFG in response to happy faces was less in the ASD group. Similar findings were also found in left superior insular gyrus and right insula in case of neutral stimulation.

Conclusion

These findings suggest that children with ASD have different processing of social and emotional experience at the neural level. In other words, the deficit of social cognition in ASD could be explained by the deterioration of the capacity for visual analysis of emotional faces, the subsequent inner imitation through mirror neuron system (MNS), and the ability to transmit it to the limbic system and to process the transmitted emotion.     

The 'amygdala theory of autism' revisited: linking structure to behavior

The 'amygdala theory of autism' suggests a crucial role for the amygdala in the neurobiological basis of autism spectrum disorders. However, to date evidence is lacking of a direct relationship between amygdala measures and behavioral manifestations of autism in affected individuals. In 17 adult individuals with Asperger syndrome (AS) and 17 well-matched controls we therefore assessed associations between MRI-derived amygdala volume and behavioral variables of emotion recognition and social cognition, as well as with core AS symptomatology. Results revealed that individuals with AS exhibited impairments in emotion recognition and social cognition compared to controls and also showed atypical relationships between amygdala volumes and overall head size. We found positive associations between emotional and social understanding and amygdala volume in the control group, but not in the AS group. In the AS group however, amygdala size was negatively related to diagnostic parameters, with smaller amygdala volumes involving higher levels of restricted-repetitive behavior domains. Our data seem to indicate that in AS the amygdala is not crucially involved in social and emotional understanding. It may, however, be a mediator for narrow interest patterns and the imposition of routines and rituals. Our data, in conjunction with current literature, seem to argue for a modification of the 'amygdala theory of autism'.     

Levels of emotional awareness and autism: An fMRI study

Abstract

Autism is associated with an inability to identify and distinguish one's own feelings. We assessed this inability using alexithymia and empathy questionnaires, and used fMRI to investigate brain activity while introspecting on emotion. Individuals with high functioning autism/Asperger syndrome (HFA/AS) were compared with matched controls. Participants rated stimuli from the International Affective Picture System twice, once according to the degree of un/pleasantness that the pictures induced, and once according to their color balance. The groups differed significantly on both alexithymia and empathy questionnaires. Alexithymia and lack of empathy were correlated, indicating a link between understanding one's own and others’ emotions. For both groups a strong relationship between questionnaire scores and brain activity was found in the anterior insula (AI), when participants were required to assess their feelings to unpleasant pictures. Regardless of self-reported degree of emotional awareness, individuals with HFA/AS differed from controls when required to introspect on their feelings by showing reduced activation in self-reflection/mentalizing regions. Thus, we conclude that difficulties in emotional awareness are related to hypoactivity in AI in both individuals with HFA/AS and controls, and that the particular difficulties in emotional awareness in individuals with HFA/AS are not related to their impairments in self-reflection/mentalizing.     

Social Skills Training for Adolescents with Asperger Syndrome and High-Functioning Autism

The effectiveness of a social skills training group for adolescents with Asperger syndrome and high-functioning autism (AS/HFA) was evaluated. Parents of six groups of adolescents (n = 46, 61% male, mean age 14.6) completed questionnaires immediately before and after the 12-week group. Parents and adolescents were surveyed regarding their experience with the group. Significant pre- to post-treatment gains were found on measures of both social competence and problem behaviors associated with AS/HFA. Effect sizes ranged from .34 to .72. Adolescents reported more perceived skill improvements than did parents. Parent-reported improvement suggests that social skills learned in group sessions generalize to settings outside the treatment group. Larger, controlled studies of social skills training groups would be valuable.     

Selective impairment of cognitive empathy for moral judgment in adults with high functioning autism

Faced with a moral dilemma, conflict arises between a cognitive controlled response aimed at maximizing welfare, i.e. the utilitarian judgment, and an emotional aversion to harm, i.e. the deontological judgment. In the present study, we investigated moral judgment in adult individuals with high functioning autism/Asperger syndrome (HFA/AS), a clinical population characterized by impairments in prosocial emotions and social cognition. In Experiment 1, we compared the response patterns of HFA/AS participants and neurotypical controls to moral dilemmas with low and high emotional saliency. We found that HFA/AS participants more frequently delivered the utilitarian judgment. Their perception of appropriateness of moral transgression was similar to that of controls, but HFA/AS participants reported decreased levels of emotional reaction to the dilemma. In Experiment 2, we explored the way in which demographic, clinical and social cognition variables including emotional and cognitive aspects of empathy and theory of mind influenced moral judgment. We found that utilitarian HFA/AS participants showed a decreased ability to infer other people’s thoughts and to understand their intentions, as measured both by performance on neuropsychological tests and through dispositional measures. We conclude that greater prevalence of utilitarianism in HFA/AS is associated with difficulties in specific aspects of social cognition.     

Brief Report: Cognitive Flexibility and Focused Attention in Children and Adolescents with Asperger Syndrome or High-Functioning Autism as Measured on the Computerized Version of the Wisconsin Card Sorting Test

The aim of the present study was to assess mental flexibility and set maintenance of a group of individuals with Asperger syndrome (AS) or high-functioning autism (HFA) (N = 13; mean age 16,4), as compared with a matched group of typically developing children and adolescents (N = 13; mean age 15,6) on the computerized version of the Wisconsin Card Sorting Test (WCST). The participants in the AS/HFA group performed less well than the controls on all categories of the WCST, but the differences did not reach conventional statistical significance on most categories of the WCST. On the category failure to maintain set, however, the AS/HFA participants performed significantly less well than the controls, suggesting a deficit of focused attention.     

Association between amygdala hyperactivity to harsh faces and severity of social anxiety in generalized social phobia.

BACKGROUND: Previous functional brain imaging studies of social anxiety have implicated amygdala hyperactivity in response to social threat, though its relationship to quantitative measures of clinical symptomatology remains unknown. The primary aim of this study was to examine the association between response to emotionally harsh faces in the amygdala, a region implicated in social and threat-related processing, and severity of social anxiety symptoms in patients with generalized social phobia (GSP). METHODS: Ten subjects with GSP naive to psychotropic medications and without psychiatric comorbidity and ten healthy comparison subjects matched on age, gender, ethnicity, and education completed the Liebowitz Social Anxiety Scale and underwent high-field (4Tesla) functional magnetic resonance imaging while viewing blocks of emotionally salient faces. RESULTS: Relative to happy faces, activation of the amygdala in response to harsh (angry, disgusted, fearful) faces was greater in GSP patients than in controls, and the extent of amygdala activation was positively correlated with severity of social anxiety symptoms, but not general state or trait anxiety levels. CONCLUSIONS: Our findings suggest that amygdala activation to interpersonal threat can be specifically linked to the severity of social anxiety symptoms of individual GSP patients, and thus, may serve as a useful functional marker of disease severity.     

An event related functional magnetic resonance imaging study of facial emotion processing in Asperger syndrome.

BACKGROUND: People with Asperger syndrome (AS) have life-long deficits in social behavior. The biological basis of this is unknown, but most likely includes impaired processing of facial emotion. Human social communication involves processing different facial emotions, and at different intensities. However nobody has examined brain function in people with AS when implicitly (unconsciously) processing four primary emotions at varying emotional intensities. METHODS: We used event-related functional magnetic resonance imaging (MRI) to examine neural responses when people with AS and controls implicitly processed neutral expressions, and mild (25%) and intense (100%) expressions of fear, disgust, happiness, and sadness. We included 18 right-handed adults; 9 with AS and 9 healthy controls who did not differ significantly in IQ. RESULTS: Both groups significantly activated 'face perception' areas when viewing neutral faces, including fusiform and extrastriate cortices. Further, both groups had significantly increased activation of fusiform and other extrastriate regions to increasing intensities of fear and happiness. However, people with AS generally showed fusiform and extrastriate hyporesponsiveness compared to controls across emotion types and intensities. CONCLUSIONS: Fusiform and extrastriate cortices are activated by facial expressions of four primary emotions in people with AS, but generally to a lesser degree than controls. This may partly explain the social impairments of people with AS.